Summat not right there. The engineer can ring and have the sync reset there and then, whilst on the phone, they *should* have done this. The only thing I can imagine is that, as happened the other day, the reset system was going slow, so the resync took well over two hours to come through .... maybe it didn't. Could be that the engineer didn't actually get the resync done, or
there is a fault on the D-side causing low sync.
Ring your ISP, and get them to call the engineers back out.