Rubikon Shipping Company DOO v Jetfly Hub SRL

Facts

The claimant, Rubikon Shipping Company DOO, a Serbian company, and the defendant, Jetfly Hub SRL, a Romanian company, entered into a contract dated 28 January 2020 ("the Frame Contract") for the sale of gasoline, an umbrella agreement for total deliveries of between 25,000 and 50,000 metric tonnes, with individual lots of 9,500–10,500 MT to be governed by written addenda. The claimant made an initial prepayment of USD 4,613,800 on 5 February 2020 for 10,000 MT due in March 2020; a first lot of 9,500 MT was in fact delivered in September 2020 under the seventh addendum, leaving USD 1,310,341.84 of prepayments outstanding. The defendant's case was that the parties then agreed that this sum would be recouped through an increased discount on future deliveries, implemented in addenda 8 to 10. A further prepayment of USD 2,730,000 was made in October 2020 but no further lots were delivered. In January 2021 the defendant sought additional payments before supplying a second lot; the claimant treated that as a renunciation and accepted it in March 2021, while the defendant contended the claimant was itself in repudiatory breach. The claimant sued for damages and, alternatively, in unjust enrichment for the outstanding prepayments, and applied for summary judgment on the unjust enrichment claim or on the issues arising within it.