are pumps for servo warm elite50 boliers still available?

hi i have a servo warm elite 50 bolier over the last 24 years not had any real problems 2 thermocuplers sorry if i spelt it wrong .had it serviced by the same people every year untill last week had to have some one else all was well untill 5 30 thursday morning i found the clock was off change the fuse clock came on ,then when i selcect it to start there was a loud ticking like sound , the company that i used for the service said it sounds like the pump & cant come untill tuesday , can a pump go just like that so suddenly ! or can i being taken for a ride & will the next thing be they say they cant get the part & surprise surprise i have to get a new bolier costing thouands all advice help gratefully recieved