I do not officially represent B&Q, but this is the kind of feedback that would never normally get through to my team, or the account managers we deal with at Valspar, when dealt with solely through the "official channels". I have made a genuine offer of help to the OP, which will also benefit me if we can establish what fault, if any, lies with the paint. If I am able to help, then procedure and bureaucracy should not stand in the way. My first and main priority will always be the customer.

Hi daliwanu, I work in the paint department at B&Q head office, and I am really intrigued to find out what went wrong with the Valspar paint you purchased on this occasion, as the premium paint you purchased is of exceptional quality, and should perform better than many other paints on the market, which is clearly not your experience. I am unable to send you a private message as my post count is not high enough, and I fear you may have the same issue, but if you can find some way of getting me your email address, we can continue the conversation in private, and hopefully reach a resolution. Thanks, Dan