I just feel it seems a little unfair for them to 'source transport' for just the cheltenham to swindon stretch, which has a lot more trains compared to melksham! what do the people of melksham do to get home?!
The people of Melksham (and the people who travel from Swindon and Chippenham to Trowbridge, Westbury and onwards too) have had plenty of practise at this, and are very resourceful
Option 1. There is at least one regular who takes his bicycle with him, and will cycle home along the Wilts and Berks canal towpath - part of the national cycling route - as it's a lovely summers evening.
Option 2. If the 19:01 on Friday does not run, they could catch the next train which is 15:36 on Saturday. (National Rail Enquiries advised me to 'wait for the next train' when I called them once in the other direction - from Melksham)
Option 3. Well dressed travellers can ask the ticket clerk in a loud voice "excuse me - the train to Melksham has been cancelled when is the next one" and - with luck - they will be overheard and one of the people from Melksham who's waiting to meet their partner off the following train from London, who will offer them a lift
Option 4. (The official one) have a word with the station staff at Chippenham who are very familiar indeed with this circumstance, and will arrange taxi(s). The staff at Chippenham do an excellent job in this circumstance - I can't praise them enough
Option 5. There is an irregular evening bus service (route 234) from the station forecourt at Chippenham which goes via Melksham.
In all seriousness, I have an overseas visitor arriving this evening from London to Melksham by public transport ... he has already been on the phone and I am heading out to 'rescue' him. The locals may be resilient and knowledgable, but tourists are not so well informed.