Expensive phone

Time: early in the morning, waiting for office to open.
Location: public phone booth.
Situation: calling a mobile number in London.

Insert coin
20p goes in. Press button to push coin in.
Credit: 20p
10p goes in. Press button again.
Credit 30p
Call mobile number...
07xxxxxxx
"Hi Malu, this is Shobana."
Credit remaining: 20p
"We..."
Credit remaining: 19p
"...just..."
Credit remaining: 18p
"...got..."
Credit remaining: 17p
"...here..."
Credit remaining: 16p
"...last..."
Credit remaining: 15p
"...night..."
Credit remaining: 14p
"...and..."
Credit remaining: 13p
"...are..."
Credit remaining: 12p
"...staying..."
Credit remaining: 11p
"...at..."
Credit remaining: 10p
"...a..."
Credit remaining: 9p
"...hotel."
Credit remaining: 8p
"OK..."
Credit remaining: 7p
"...I..."
Credit remaining: 6p
"...will..."
Credit remaining: 5p
"...call..."
Credit remaining: 4p
"...you..."
Credit remaining: 3p
"...back..."
Credit remaining: 2p
"...later..."
Credit remaining: 1p
"...bye."
Credit remaining: 0p