Charging error / money

I started using lightroom etc on my ipad, paying the small amount of £5 a month something for better features within the app. However, recently I decided to upgrade buying the £9.99 a month package on my laptop and creating a proper account. However, I am now being charged for bith the only package I had on my iPad and the new one I have set up, despite being logged in with my account now on my iPad as well as my laptop. I cannot seem to find a way to cancel the payment on my the app at all or find an email address to contact customer services: does anyone know how to do this, so I am only charged the £9.99 a month? - also any possibility of getting a refund?