If we get to our maximum limit of transactions before the end of the year we’ve signed up for, what would happen?

If we get to our maximum limit of transactions before the end of the year we’ve signed up for, what would happen?

The transactions are reviewed on a quarterly basis. 
If you join today as a low tier member (max 100 transactions included) and in three months’ time you've done 105 transactions, for the next quarter we'll adjust your Direct Debit and put you onto the medium tier.
However, if you're on the medium tier and for the next quarter only do 50 transactions, then we will change the Direct Debit and adjust your tier to the lower one.