The Big Brother host presented the weekday morning show, usually filled by Ken Bruce, last week.
The BBC confirmed 156 people had complained and others posted negative comments on its internet messageboards.
Listeners complained about her "inane chatter" and called her "cringe-worthy".
In a statement the corporation said it "fully recognised the strength of feeling" but defended choosing McCall.
It said: "Davina has a chatty style of presentation and we feel this is in keeping with fellow Radio 2 presenters, such as Chris Evans and Dermot O'Leary.
"While we appreciate that Davina's style is different to Ken's, we are also getting a positive reaction from some Radio 2 listeners who are really enjoying the show."
Bruce is away for a fortnight but will this week be replaced, as previously planned, by singer Aled Jones.