BPA (the respondent) sued the appellants for outstanding diesel debt. In 2001, BPA concluded an agreement with the Albertinia Dekriet Trust for the supply of diesel to refuel the Trust's trucks. Ms Müller signed a credit application form and suretyship on behalf of the Trust. In 2003, Mr Otto of BPA approached Ms Müller to open a diesel depot on the Trust's premises to supply diesel to the Trust and the public. This required upgrading from a 9,000 litre to a 23,000 litre tank. The Trust fell into arrears, owing approximately R7 million. BPA sued the Trust (represented by trustees Mr Marais and Ms Müller) and Ms Müller personally as surety. The appellants contended that the 2003 depot agreement was a new oral agreement with Ms Müller personally trading as Albertinia Diesel Depot, not an extension of the Trust's agreement. They argued the Trust never traded in petroleum products and that Ms Müller sold the depot in October 2008. All invoices, statements, and VAT registrations continued to reference the Trust. The trial court found dissensus but applied quasi mutual assent to find the Trust liable.
The appeal was dismissed with costs. The High Court's finding that BPA contracted with the Trust (not Ms Müller personally) was upheld.
A party suing on a contract bears the onus of proving the contract sued upon, including proving that it contracted with the defendant and not some other party. Where a business relationship continues at the same premises, with the same people, and involving the same subject matter, with continuity in documentation (invoices, account numbers, VAT registrations), the court will find that the original contract has been extended rather than replaced by a new contract with a different party, absent clear objective evidence of novation or substitution of parties. Subjective understanding or intention of one party is insufficient to establish a new contract where objective evidence consistently points to continuation of the original contractual relationship. A plaintiff's claim will succeed where the defendant's version is contradicted by contemporaneous documentary evidence and lacks objective corroboration.
The Court observed that the High Court erred in placing the onus on Ms Müller to prove she was the debtor, when the onus properly rested on BPA to prove its contract with the Trust. However, this error did not affect the outcome as BPA had successfully discharged its onus. The Court noted that Mr Otto's difficulty in recalling details of events 13 years prior was understandable and should not automatically discredit his evidence, particularly where his core evidence remained consistent and was corroborated by documentary evidence. The Court commented that if BPA had truly contracted with Ms Müller personally in 2003, it would have assessed her personal creditworthiness rather than relying on the Trust's established credit facility. The Court also observed that Ms Müller's application for a depot license in 2007, after receiving a demand letter, appeared to be a belated attempt to distance the Trust from liability.
This case clarifies important principles regarding proof of contractual relationships and the extension versus novation of contracts. It emphasizes that a party alleging the existence of a contract must prove it through objective evidence, not merely subjective belief. The judgment demonstrates the importance of documentary evidence (invoices, VAT registrations, bank details) in determining the true nature of commercial relationships. It establishes that where parties continue dealing in substantially the same manner after alleged contract changes, courts will scrutinize claims that a new contract was formed with different parties. The case also reinforces principles regarding onus of proof in contract disputes, clarifying that a plaintiff suing on a contract bears the onus of proving that contract, even where a defendant raises an alternative version. The judgment provides guidance on assessing witness credibility, particularly where long periods have elapsed and witnesses struggle with recollection, emphasizing that evidence must be evaluated as a whole mosaic rather than in isolated fragments.