Subway in the town's market square was closed between July 16 and August 16 last year after Telford & Wrekin Council inspectors found cockroaches crawling over shelves and food preparation areas.
The food business operators, Gurdeep and Simmerjit Sandhar, were this week fined more than £10,000 in total after accepting the store broke EU food hygiene rules at Telford Magistrates Court.
Today Subway said the shop had a top hygiene rating before the infestation and has achieved another high rating since.
A Subway spokeswoman told the Shropshire Star: "Operating with strict hygiene standards is a mandatory requirement for any Subway store. The franchise owner has confirmed that prior to its temporary closure in July 2018, the store held a FSA food hygiene rating of five (very good) continuously for 10 years.
"Since reopening in August 2018, strict cleaning standards have been maintained to ensure excellent hygiene and there have been no pest control issues. As a result, the store was awarded a FSA food hygiene rating of four (good) in March 2019. The franchise owner is committed to making continuous improvement so valued customers can have complete trust in their Subway experience."
A member of the public raised suspicion to the council after seeing a member of staff knock a cockroach off a food preparation area while making a sandwich, and carry on preparing the food without washing their hands or disinfecting the area.
The employees involved were summarily dismissed after the inspection, the court heard on Monday.