Good air conditioning expert needed Soton/Winchester area

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Anyone know a good air conditioning expert Southampton/Winchester/Romsey area? Both of those I've used in the past have gone. I have a Peugeot 306 which is full of gas with a working compressor (pressures are good, responses to controls are correct) but the cooling has become feeble and from the noises from vicinity of the bulkhead I suspect I have a failed or blocked expansion valve. I've called in to a couple of places which advertise that they do aircon and had to walk away as even that description was beyond them and they clearly only re-gas and send you on your way.