Support staff (Tristan) does not do what is promised - won't take blame for anything

We initially signed up with Nepic - then signed up for fibre through Blitz, who transferred our line to Frogfoot, who transferred our line to Supersonic. However, the final 'transfer' hasn't been done properly. I have called all parties, and all are blaming each other saying they can't help. I phoned Nepic last night and believe I spoke to Tristan (or similar). He promised me he would put me in touch with his manager in the morning. It is now 11am and no one has tried to contact me to resolve. This is extremely frustrating.