radiators cold .... brrrrr?

Hi had one new rad fitted in bathroom, pipes to accept new rad adjusted accordingly (different width) !! New rad given to plumber to adjust. He abandons me. Another plumber taken on he had to bend the pipes with a burner in bathroom to fit> Now no rads are warming up whats wrong ???? First plumber wants his money after abandoment and the second ive paid... Oh what a fool. The second took a rad of downstairs as the combi boiler upstairs to drain system. Can any one help I just keep paying people left, right and centre.