You will receive one invoice for each service provider (SP) you purchased services from, each month.  So, if you have purchased 10 services from SP1, 3 services from SP2, and 33 services from SP3, at the end of the month you will receive 3 invoices. 

Of course, you have already paid for these services, so the invoice has already been paid for. All you need to do with the invoice is set it off against the outstanding cinvio amount on your balance sheet. This invoice includes the exact VAT details for a correct VAT declaration.