MAM Ultivent Anti Colic bottles- anyone else's leak?

[1Baby1Bump]

Has anyone else spent an arm and a leg on these things only to find now they are about 6 months old they leak?
I'm so bloody angry about this!

I only bought mine last week and they seem to leak! The teat seems to slip between sterilising and adding powder - soooo unpopular at 3am.
I'll be surprised if mine last 6 months

i found with the initial leaking, putting some boiling water in them a few times from cold sealed them.
put it in, wrap them in a tea towel then shake. whilst still wrapped unscrew top (will make an awful squeaking sound) then empty and use as normal.
they didnt leak after about doing this 3 times. they have started again now though!

I only had one and it leaked about 50% of the time, from the start. Didn't use it for that long, obviously!

I used the teats though, on other wide-neck bottles. They were great!