Comma-separated lists with no spaces are interpreted as one long number

[disgustingwall]

A list with no spaces is interpreted as a long number, and therefore converted to a long number. Instead, each number should be converted individually after the sequence is identified as a list.
For example, "1,2,3,40" is converted to "twelve thousand three hundred and forty" but should be "one,two,three,forty". In this case, the commas clearly do not represent a digit separator for convenience, as there are series of numerals that are not three numerals long to the right of each comma.
Whether a comma separated list of numeral triplets, possibly preceded by a numeral duet or singlet and a comma, is a list or a single number is ambiguous. In this case, the ambiguity is due to lack of information in the original formatting, so it should be treated as a single number.