Communication Problems (a.k.a. Theft) - S2-E1
Plot hole: Basil torments Mrs. Richards by miming when he is speaking to her, so she will think her hearing aid has failed. However, she speaks twice during the scene, and she would hear herself - obviously - and would know that he was trying to fool her.
Communication Problems (a.k.a. Theft) - S2-E1
Visible crew/equipment: In the scene where Polly tells Manuel to go and fetch toilet paper for Mrs Richards, the boom microphone shows up at the top left for a few seconds.
Communication Problems (a.k.a. Theft) - S2-E1
Continuity mistake: During the opening scene where Polly is arguing with Mrs Richards over "giving change", the loose papers on the reception counter keep disappearing and re-appearing between shots.
Answer: It's "Leisure Complex" by Dave Gold and Gordon Rees. Can be found on YouTube. The relevant clip is around 25 seconds in.