check your local yellow pages or do a google search - there are companies that specialise in repairing this damage. a local one near me is called 'chips away', never used them but heard that they are pretty good. and not as expensive as you may at first think.
It really depends on whether an "obvious" repair or whether price drives your decision first and foremost. You can buy a repair kit, which will protect the metal below, but the repair will be clearly visible. Chris_on_tour is right that you can get specialist repair companies that will do this for you. Don't think Chipsaway will do this as unless things have changed, they only work on cars. Found this company on internet, but you no doubt can find others doing much the same thing. Google "surfacedoctor.co.uk" . Hope this helps.
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