How to record a bank deposit as a payment from customer even though there arent matching invocies...

Hello, 

I have started using quickbooks after using different software. I connected my chequing account to quickbooks. Many of our customers pay us through cheques which we edeposit in the bank. I'm adding old data from q1 of 2020 to now. I cant import invoices into QuickBooks so I imported customers and added their opening balance. Now their opening balances dont match one single transaction in my bank records. I put their opening balance and then I have multiple payments received from then to now for multiple invoices which quickbooks does not have, it only has one big open balance. Now when I select bank deposits, select my customer in payee and choose the account as accounts receivable. when i go to the customer in sales it shows one big invoice and multiple deposits is there a way to make these appear as payments towards their opening balance. I know there's the receive payment button but it is alot of work to enter all the payments manually and then manually match in my bank. is there a better way to do what im doing...