Returns Label

I bought two sizes as I have not bought Funkita before, so I have returned one of the sizes, and kept the other.
I am sure that the system will work well, but concerned that the small print on my invoice states that I will have £3.00 deducted from my refund, even though I have paid already paid £3.95 for the returns label. Is this correct?

Easy to use website, quick supply of goods, perfect fit and excellent value for money, granddaughter is super pleased plus unused returns voucher

I haven’t used this label & would quite like a refund. It wasn’t used because the product was excellent & didn’t need to be returned.

Really comfortable swimming costume. Nicely covered back and supportive front for a chubby person!