Help using csvread to combine and reduce CSV files; Error using dlmread (line 147) Mismatch between file and format character vector.

I have 47 CSV files of 60005 lines that look a bit like this

I want to create a matlab script to load them all into one matrix, reduce them, then save to xlsx like this, but it doesn't work.

clear all; clc;
files = 47;                                         % number of CSV files
rows = 60005;                                       % rows in each CSV file
totrows = rows*files;                               %number of fiels times number of rows 
maxallowedrows = 1048576;                           %max allowed .xlsx rows
frequency = totrows/maxallowedrows;                 %frequency i need to reduce by
frequency = ceil(frequency);                        %round up frequency to integer
CSV = [1,2,3,4,5,6,7,8,9,10,11,12,13,13,14];        % create CSV matrix for file
for file = 1:files                                  % for every file
    fnum = num2str(file);                           % convert file number to string
    filename = (['THERMAL_VTC6_',fnum,'.csv']);     %create file name
    CSV = [CSV; csvread(filename,5,1,[5 1 rows 14])]% load file and add to bottom of matrix
end                                                 % end loop

for mycycle = 1:totalrows
    if isinteger(mycycle/frequency)
        for A = 1:14
            XLSXfileadd(1,A) = CSV(mycycle,A);      % sample every line that is divisible by frequency
        end                                         % end loop
        if mycycle ~= frequency
        XLSXfile = [XLSXfile; XLSXfileadd];         % if not first file then add to bottom matrix
        else
        XLSXfile = XLSXfileadd;                     % if first line then create matrix, do not add as it doesnt exist yet
        end
    end                                             % end loop
end                                                 % end loop

I get the error

Error using dlmread (line 147)
Mismatch between file and format character vector.
Trouble reading 'Numeric' field from file (row number 1, field number 7) ==> /09/15
09:31:18,100,3.5273,2.0007,0.0001,0.0002,0.0001,StepRunning,27.8992\n

Error in csvread (line 50)
    m=dlmread(filename, ',', r, c, rng);

Error in CSV_Combine (line 12)
    CSV = [CSV; csvread(filename,5,1,[5 1 rows 14])]% load file and add to bottom of matrix

I believe it's something to do with the text columns in my file not working with CSVread

Thank you in advance for your help

Ben