Firstly: "war-torn Cameroon" - what unmitigated rubbish! Post-colonial Cameroon has been amongst the most stable countries in Africa.
Secondly: Unlike many countries Cameroon has free political parties and an open press who are not afraid to criticise the government.
Thirdly: "political reasons" are very rarely the cause when people have a run-in with authority; it is usually because they have offended someone or an individual has a grudge against them. [I have seen this happen and because Cameroon operates the system of "guilty until proven innocent", people often end up in goal for no good reason other than the unreliable word of another.]
Fourthly, if someone doe not agree with your political views, it does not give you the right to feel persecuted.
All of this does not currently justify being allowed to claim asylum in the UK. Cameroon is a country which Britain regards, quite correctly, as being safe and in comparison to many others (Zimbabwe, Somalia, Afghanistan etc.), this is probably true.
It is a shame that "celebs", who probably know nothing about Cameroon other than what they are told by people with a degree of self interest, are dragged into giving their backing.