Judge rejects section 21 as weekly payment ticked on AST on standard AST issued by RLA

Possession - Section 8 and Section 21

The standard AST issued by RLA was used for a six month rolling tenancy agreement, which indicates it is a monthly rolling contract. However the rent payment was ticked as weekly. The judge statement is as follows
The claim be struck out pursuant to Part 55.16(1)(c)
Section 21 notice expired on07 Aug 2011, which was aFriday. When fixed term tenancy exceeded, a weekly tenancy arouse on ......... The last day of a period of that weekly tenancy would have been a Tuesday, not a Friday.
Do I have a case to argue that it is Monthly rolling tenancy when I had weekly rent amount ticked ? The rent was however actually paid monthly and always late and lower that the quoted amount ?