According to the municipal contract, the works were to be paid upon completion. A few months later, the parties entered into an additional agreement and provided for the payment of an advance.
The Prosecutor's office demanded to recognize the transaction invalid, and also to oblige the executor:
return in full advance to the customer;
to pay interest for the use of other people's money.
The courts supported the claims, except for the requirement to return the advance, since the contract had already been executed.
Document: Resolution of The arbitration court of the Volga district of 23.09.2019 in the case N A72-16393/2018