I believe I do have a timeline of events that you might find educational.
Russ is being harassed by a bully named Craig. When Craig hits him, Russ exclaims: “Oi! Half a glass!”
Craig then takes Russ’ guitar, but loses interest when Russ refuses to fight him for it, so he returns it.
Russ, realising he will be late home, asks Craig for 20p to call his parents. Although the sum is revised to 10p, Craig does give him the money under the instruction that he tells no-one.