I had previously paid 16 a month for the creative cloud however it suddenly started charging me more despite the offer still being available I don't understand why this happened or how I can get a refund for the extra I paid despite recieving the exact same products.
The introductory pricing is only available to new users, and is only for the first year of the subscription.
Have you had your subscription for a full year and just started your second? If so, the introductory pricing is no longer available to you. Once the first year is finished, you are charged the subscription at its full price.