Section 47 and 48 question_ can I claim my rental payments back?

Other

For the last 12 months I have been paying rent (via DD) to a landlord who refuses to give me their home address. My last DD did not go through and as the landlord now wants to charge me daily interest, I am keen to clear this small dept with immediate effect by paying the landlord in cash. I keep emailing the landlord (whose email I found out by default as they had refused to give it) - asking where I can drop the cash off to clear the unpaid amount in cash.

The landlord still refuses to give me this information. I am a landlord myself but with their full permission I re rent the property out as a Corporate Let.I have read about Section 47 and 48 and I am now wondering if I can claim back the last 12 months rent I have paid them as it appears the contract I had with them may not be legal.
On top of this, the landlord has just sold the property and is serving me with notice. Is this legal when I do not have their address?

Anyone here experienced this?