Campbell joined the Midlands club, where former England boss Sven-Goran Eriksson has been installed as director of football this season following its takeover by a middle-eastern consortium, but after playing in last week's 2-1 defeat by Morecambe, left "by mutual consent."
"I knew I would be the club's first big signing but was told I would be the first of many. Names like Roberto Carlos and Benjani were mentioned. But nothing materialised," Campbell told Sunday's News of the World.
"The only thing I'm guilty of is taking people at their word. So I'm not embarrassed, not hurt or humbled or anything like that - I am just disappointed.
"I bought into a dream and I wanted to make that dream a reality. But it took me less than a month to realise that it was all heading to a different conclusion," added Campbell, who once walked out on Arsenal at halftime during a game.
However, Notts County chief executive Peter Trembling said that the club had made quick progress and denied touting the names Campbell brought up.
"I'm a bit surprised by Sol's comments," he told BBC Radio 5-Live. "Things have gone at an astronomical pace over the last few months.
"Signing nine players in three months is unheard of at our level and we've started work on a new training ground.
"We've been linked with about 88 players but I've never talked about Benjani to anybody at all. Roberto Carlos - Sven, I understand, did talk about but it never went beyond a conversation.
"Sven talks every day about four or five players we might be looking at - but most are more aligned to League Two."
Trembling added that though the identity of the group who have taken over the club remains something of a mystery, the Football League is happy with the situation.
"They've quite rightly asked more questions about the investors - an overseas private investment trust," he said.
"We've no issues with that and have given them everything they need thus far. "The League have a board meeting on October 8 and have said if they know anything they'll come back to us. We've answered everything we could have so far.
"It would help if one of the major shareholders would put their head above the parapet but we are being pilloried for putting money in oldest club in the world.
"As far as we are concerned we have nothing to fear. All we want to do is invest in this club and make it successful."
