3 different renewal prices - any idea why?

I went onto iTunes to check when my subscription expires (February), and saw that there are 3 options for renewing the sub:

Memrise Pro (1 year) £13.49
Memrise Pro (1 year) £22.49
Memrise Pro Offer (1 year) £35.99

If I select one of the options, I get a message to say that if I renew now I’ll get a refund for the period between now and the end of my current subscription.

I’d happily renew for £13.50, but I just don’t know why there are these three options, or what the difference is - does anybody know?

Thanks!

Hey there!
I have the same issue, and have tried to find out why this is the case, did you manage to find out why there are different prices?
Thanks in advance

@MemriseMatty: could you shine any light on this? Thank you!

I found this:
Subscription automatically renews unless auto-renew is turned off at least 24-hours before the end of the current period
your account will be charged for renewal within 24-hours prior to the end of the current period, the cost of renewal will be $8.99 (USD) for Monthly, $18.99 (USD) for Quarterly, $59.99 (USD) for Annual, $45.99 (USD) for 20% discounted Annual, $29.99 (USD) for 50% discounted Annual and $17.99 (USD) for 70% discounted Annual or an equivalent of the Territory country pricing.

https://www.memrise.com/terms/