Ammending reports?!

I rang to request my assessment report the following day after my assessment (27th june). I was told then that it would be sent out within 7 - 14 days. Rang again on the 10th july as still nothing recieved, told they only had the report on the 7th so will take until 19th july to be sent to me. Still nothing today but got a basic letter saying they had all the information they need to make a decision. Rang to enquire again what was going on and why no assessment report and told this time by the Cholton service centre, that they do not send out the reports until a decsion has been made. He confirmed this was a new thing but when I queried when the change came in he said within the last 5-6 weeks. He added that the reports are not "finalised" until the decision has been made so if I was to recieve it it would not make sense as they had not finalised and make any neccesary ammendments to it!!! Is this even legal for them to make changes to the report????? I raised my concerns with him but he just apologised and said that they are sticking within guidlines but surely this is not right??

Thanks gordon. Are they allowed to ammend assessors reports though?