Ince's tenure at Bloomfield Road was ended on Tuesday, after a poor run of form saw Blackpool collect just one point from their last nine Championship games, with assistants Steve Thompson and Alex Rae also leaving the club.
Reports that the 46-year-old learned of his fate via text message were confirmed by Oyston on Wednesday, who felt he had little choice as Ince had not informed him he was attending a coaching course
Ince confirmed his involvement in the course, but said he had no idea that he, nor any of his coaching staff, would lose their jobs in a meeting with Oyston last Sunday.
A statement released through the League Managers Association read: "It was deeply disappointing to have been notified that my contract was to be terminated via text message after a lengthy meeting with the club chairman on Sunday where no indication was given that any of the coaching staff, myself included, were going to lose their jobs.
"Neither I nor my coaching staff received a telephone call from the chairman at any stage after this meeting.
"It is true that I was at St George's Park this week as I am completing the final phase of the UEFA Pro Licence, which I have been working towards over the past two years.
"Along with others in my position, I have attended several such training days throughout this period."
Ince also refuted rumours he had failed to provide a list of targets for the January transfer window.
He added: "It also disappoints me that I have been accused of failing to produce a transfer target list.
"We had identified key targets in the January transfer window to improve the squad as a result of injuries to key players and the loss of four loan players who returned to their parent clubs.
"The need for new faces at the club could not have been more evident than at the recent home match against Middlesbrough where we had two young players on the bench who had already played in another match that morning."
