Currency not showing as it should also currency stuck on mobile sites.

Hello, some of my products are not showing the correct price, for example if i have a product priced at £14 it is showing $14 when i select the currency as USD, this is not on all products just some of them. Also, my other problem is that when I view my website on my mobile the currency is stuck on USD even though i have turned the auto detect off and select GBP it still stays on USD.

This is really not good, I have paid for this plugin and have all of these problems and have had to disable the currency bar to avoid losing purchases, please advise?