Hotpoint fridge freezer ff175m door not closing?

Hi, I had to defrost my fridge manually and now the fridge door won't close keeps opening. I have to hold it with something to keep the door closed. I have done nothing to the door when defrosting apart from stretching it open to get the shelves back on. Pulling my hair out can't work out what could i have done to cause this as it was closing fine before i defrosted the fridge so for the rubber seal to wear out in minutes does not justify it.Any suggestion is much appreciated. P. S the door closed find before the defrosting method. Thanking all in advance

Baz
October 2011