dont know if this will be much help but do the makers of the pump not have a website which may offer help contact addresses etc.
Owner of 10 goldfish, Custard, Speedy, Spot, Natalie, Colonel, Goldy, Bulldog, Blackie and Pete and Sick Note and now five new babies that have bred in the pond,(oh and 1 plastic duck, 1 rubber duck, used to be 2 rubber ducks but the lawn mower at...
Exactly what part is damaged? I think the screen cases and the impellor housing are available, if the former, get or ask for the later version, it has better catches. If the latter try gluing it with model aircraft or solvent weld glue, from memory its ABS so the solvent weld glue should work and that smells just like airfix glue. If it is the casing around the actual windings of the motor your are looking at a new pump sorry. Sometime Hozelock's cs is not so good other times its brilliant. Recently my just over 2 year old titan packed in, I posted a letter to them on a Thursday which contained photo copies of the credit card counterfoil and statemnts, I had lost the original receipt. Over the weekend I emailed them a copy of a proof of purchase written by the shop and I had a replacement pump either Monday or Tuesday morning.