Services delivery and number of services delivered

Hi and greeting to all the community.I would like to ask if there is a way to have services number in an invoice.i know that this can be done if i use products which there i can have a warehouse-deliver goods-subtruct from warehoush and order.But in services mode for example a freelancer tech can sell a contact of 5 tech visits or 10 piano lessons and want in every visit to give a receipt for the service.In the receipt there can be a value with vat or only receipt with the remaining services left after the visit.In products you can deliver goods but you have to build an invoice for all orders not only the ones you are sending.Is there any future update to dolibar that could addres this?

May be you can use the intervention module to track each visit and keep invoice to build a global receipt for all visits.

Thanks eldy.Its a good work around as you can see the amount that has left with the customer.It will be great if at the intervention we could choose the invoice and then in the intervention invoice we could have the services that was billed in the invoice.
second There is a problem with the financial problem.If you choose to do payment back to close this intervention then you will have some black hole in the financial account as you have been paid for some services and then when you are fulfilling the service eg piano lesson you are also giving back the money with the receipt.