Impulse Sealer

i bought one the other day because i thought it’d be good to seal bags i was putting xmas goodies in… but the damn thing wont work! what am i doing wrong? i hold it down for 3 seconds, or longer.. and slide it along… and NOTHING bloody happens. i even took out the new batteries and put different new ones in… blah! should i just take it back where i got it and try exchanging it? or do these things really NOT work.

I saw a website that is a mail order catalogue (can ordero nline too) for one of them.
Does anyone know where I can get one cheap??
Please do not tell me to look on ebay. I do not and will not use that site

I can’t stand those things.