By your description of the work needed, it certainly sounds like the pipes are seriously deteriorating (from the inside), or possibly broken, sagging, or even offset if the blockage is outside of the structure en route to a city main or septic.

Had it camera ran down about 300 Showing me where the blockages were happening, and how deep.

Is they're roots cause the blockage ?

Talk to them and ask them to diagnose for free, but if it is a blockage due to other sections of pipe or improper waste in the drain, that is going to be on you.You may also want to call the city and check with them, especially if you had heavy rains before it happened.

do you have to pay anythign each time you use the service or if they find any other blockage or broken pipe do they cover ?

Also for the first time, you have no way of knowing if it was the current tenants or a previous one and something happened later to cause the blockage.

For example, my lease states “Tenant shall be charged for repair of drain blockages or stoppages, unless caused by defective plumbing parts or tree roots invading sewer lines.”So, having not read your lease, we couldn’t say for certain who is responsible for the cost.

However, the blockage continued as it was, so he had to come out again and have a look the week after.

The City has made it very clear to property owners that if they are required to clear a lateral due to a blockage resulting from wipes, the property owner will foot the entire bill.We have likewise made it very clear to our tenants that the use of wipes is prohibited in our properties and any costs incurred to clear an obstruction resulting from their use will be passed along to the tenant.We had one instance in November where tenants use of wipes managed to clog a backflow valve at one of our properties.  

While fix underway plumber also stated blockage was caused by a kids ball in the line.