I have bought a spray collar back in February for £70 and although it is effective, i have had to return it twice now to be fixed for the same thing, mainly that the refill valve keeps sticking, so that all the spray contents leak out, or you can't refill it as the valve is stuck in. After talking to the people who fixed it i get the impression that these things are badly designed/made as they had loads to repair, so has anybody had problems with these collars and if so what?. I am considering trying to get my money back if mine goes wrong again,( it costs (£4 a time to post it off for repair) at £70 a go i would expect a better product.( i'm not denying that they aren't effective when they work, it's just that they don't seem to be reliable.