Exmobank granted CJSC Triton a bank loan

Exmobank granted CJSC Triton a bank loan

Exmobank granted CJSC Triton a bank loan, transferring in March 2004. loan amount to the current account of the borrower. Together with the borrower, responsibility for the fulfillment of obligations to repay the loan and pay interest was assumed by the Zavod LLC, which has a current account on the basis of a letter of guarantee.
By the deadline, the borrower did not repay the loan, in connection with which the bank recovered the loan debt and interest for using it with Zavod LLC as a guarantor and demanded payment of the penalty for late repayment of the loan from CJSC Triton as a borrower.
Is the bank legal in this situation? Could a letter of guarantee be used as a way to enforce the obligations?

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