You must be joking !!!???
I can only assume you are in 'Troll' mode for a laugh.
1st problem is the disconnect between you and OR, you cannot escalate anything to OR after a callout and OR will only respond to the ISP raising a call for a specific set of criteria that match the support contract the ISP has with OR.
If you don't match the criteria OR does not respond, even if the problem is a follow-on from a callout they will not respond. Each callout is a separate issue and is judged on the specific criteria in isolation.
BT/Openreach & ISP's decide what is or is not a fault, the game they play is that 'if' the Openreach Engineer cannot find a fault then you are charged a callout fee.
The problem is how hard the fault is to find and if not found it makes any future attempts to resolve it harder.
If the OR Engineer has already decided there is no fault they tend not to look too hard !!!.
It has taken 18 months to get a problem resolved because the ISP did not have a 'script' to match the issue so I ran into a brickwall trying to log the fault to begin with. OR then sent 4 sets of Engineers [over 18 months], First set of OR Engineers did not understand the issue and left the line in a worse state than it was in before he arrived. The next OR Engineer (6 months later) had already decided there was NO Problem and was gone in minutes. Two other sets of Engineers did find a fault that was only resolved because the last OR Engineer was prepared to invest a little more time and eventually improved the line.
The line is still NOT completely fixed but I cannot afford to waste months chasing the ISP/OR when I may get a worse line as a result. (That is what I got with the 3rd set of Engineers who stated it was the best I could get BUT the 4th set of OR Engineers thought otherwise.)
Full saga much much longer and with lots of detail but it will be TL;DR :)
Lots of reports of people being charged for a callout which does not fix the fault BUT as it cannot be found, problem does not exist ....... Ka-ching Pay up !!!
It does tend to put you off attempting to convince the ISP to push a problem to OR in case it costs you and the problem is NOT fixed either.
All the tests are based on 'what I can detect now !!!' yet if you have historical data logging the fault it is ignored, usually with the parting line 'It appears to be working now !!!'.
The ISP & OR have historic data on the line and DLM is monitoring the line continuously, yet the OR Engineer does a 1 time test and declares the line is working. They often say just log another call if the problem comes back BUT most ISP's will only escalate to OR if forced and having a call that was 'proved false' makes them even more reluctant to escalate in the future.
Don't get me started on the nonsense that is DLM and how it is more a problem than a solution to getting the maximum speed & quality from your line.