Rent increase following a fixed term expiry, despite agreement saying 12 months

Hi all,

We have a dispute with our letting agents / landlord regarding a rent increase following the expiry of a fixed term tenancy which was for 6 months.
Our signed tenancy agreement quite clearly states that a rent increase can be applied every 12 months on the anniversary of the date on which the tenancy began.

The government website states:
How your landlord must propose a rent increase

** If the tenancy agreement lays down a procedure for increasing rent, your landlord must stick to this. Otherwise, your landlord can:**

** renew your tenancy agreement at the end of the fixed term, but with an increased rent**
** agree a rent increase with you and produce a written record of the agreement that you both sign**
** use a ‘Landlord’s notice proposing a new rent’ form, which increases the rent after the fixed term has ended**

However another part states:
For a fixed-term tenancy (running for a set period) your landlord can only increase the rent if you agree. If you do not agree, the rent can only be increased when the fixed term ends.

From where we stand, I feel that we were not clearly made aware that the rent could be increased inside a 12 month period, but does the fixed term coming to an end overrule this?

Thanks for any advice!