The 27-year-old was out of favour under Westley and was transfer listed at his own request in January.
Since Westley's sacking, Randall has returned under caretaker boss Mike Flynn and was an unused substitute in the last two games.
"I thought Graham Westley treated me quite unfairly," he said.
"I'm happy to be back and hopefully I can contribute to Newport staying up."
Ex-Arsenal player Randall, who joined Newport on a two-year contract in May 2016, last played for the Exiles on 21 January in the 0-0 draw away to former club Barnet
County have won two of their three games since Flynn took charge, although they are seven points adrift of safety in League Two
Randall said there was a "good vibe" under Flynn and is looking forward to be involved in the side's bid to escape relegation.
"I've been off for a few weeks and got to get my sharpness back," Randall added.
"Everyone seems a lot happier and there's a lot more energy around the boys.
"We feel confident now that we're going to put up a really good fight and we've got enough energy to run around, which I think we struggled with."
Midfielder Mark Randall is happy to back at Newport County and says he was "treated quite unfairly" by former manager Graham Westley.