How to change image on button pressed with cell reused - ios

Question

There is a problem. I need at the touch of a button to add to the array and at the button to change the image.
I do it this way:
- (IBAction)addUserAction:(UIButton *)sender {
CGPoint touchPoint = [sender convertPoint:CGPointZero toView:self.tableView];
NSIndexPath *clickedButtonIndexPath = [self.tableView indexPathForRowAtPoint:touchPoint];
NSInteger row = clickedButtonIndexPath.row;
UserCell* selectedCell = [self.tableView cellForRowAtIndexPath:clickedButtonIndexPath];
NSString* login = selectedCell.loginLabel.text;
BOOL userIsExist = selectedCell.isExist;
for (QBUUser* user in self.users) {
if ([login isEqualToString:user.login]) {
if (!userIsExist) {
[self.assistant.usersInCurrentChat addObject:user];
userIsExist = YES;
UIButton* button = self.buttons[clickedButtonIndexPath.row];
[button setImage:[UIImage imageNamed:#"delete_icon_64x64.png"] forState:UIControlStateNormal];
self.buttons[clickedButtonIndexPath.row] = button;
} else{
[self.assistant.usersInCurrentChat removeObject:user];
userIsExist = NO;
UIButton* button = self.buttons[clickedButtonIndexPath.row];
[button setImage:[UIImage imageNamed:#"add_button_64x64.png"] forState:UIControlStateNormal];
self.buttons[clickedButtonIndexPath.row] = button;
}
}
}
selectedCell.isExist = userIsExist;
}
my Code for cellForRowAtIndexPath:
- (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath {
UserCell* cell = [tableView dequeueReusableCellWithIdentifier:#"userCell1"];
if(!cell){
cell = [[UserCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:#"userCell1"];
}
QBUUser* user = [self.users objectAtIndex:indexPath.row];
cell.loginLabel.text = [NSString stringWithFormat:#"%#", user.login];
NSInteger currentTimeInterval = [[NSDate date] timeIntervalSince1970];
NSInteger userLastRequestAtTimeInterval = [[user lastRequestAt] timeIntervalSince1970];
// if user didn't do anything last 1 minute (60 seconds)
if((currentTimeInterval - userLastRequestAtTimeInterval) > 60){
cell.statusImageView.image = [UIImage imageNamed:#"offline_icon_45x45.png"];
} else{
cell.statusImageView.image = [UIImage imageNamed:#"online_icon_32x32.png"];
}
NSInteger row = indexPath.row;
if ([self.buttons[indexPath.row] isEqual:[NSNull null]]) {
self.buttons[indexPath.row] = cell.button;
} else {
cell.button = self.buttons[indexPath.row];
}
return cell;
}
But the cell "reused" and I get the result as in the picture my bug
How do I fix this ?